The victims included two males and a female, said Officer Karen Rayner.
Two were critically wounded and two others were considered stable, said Foothill Station Duty Officer Gerardo Mejia.
Two males dressed in black were seen walking away from the shooting scene, Rayner said, adding the incident was likely "narco or gang related."
Anyone with information about the shooting or what preceded it was urged to call the Foothill Station at (818) 756-8861.
